1a. Objectives (from AD-416):
Improve NOW control and mitigate MRL-issues by mapping the environmental fate and transport of contemporary insecticides.
1b. Approach (from AD-416):
Utilize a cooperative effort between USDA-ARS, University of California at Irvine, University of California at Davis, University of Nevada at Reno, and industry to provide a comprehensive strategy for using chemicals to control insect pests in California Pistachios. We will specifically: evaluate the insecticidal activity of insecticides on nut surfaces, characterize the chemical residual of insecticides on nut and leaf surfaces, quantify relative stability of insecticides to water and sunlight, profile the metabolic processing of insecticides by key fungus in orchards, break MRL-related trade barriers involving insecticides, integrate results into a comprehensive chemical control strategy, and support other pistachio researchers evaluating resistance management programs, spray drift, and water contamination.
3. Progress Report:
This Trust Agreement was established to support Objective 1 of the in-house project and is related to finding production techniques that ultimately reduce the requirements for standalone postharvest fumigation with methyl bromide. The goal of this project is to ensure strategic application of chemicals to control navel orangeworm (NOW) in almonds by mapping the environmental fate and transport of insecticides, particularly degradative pathways involving solar photolysis. The direct photolysis products of bifenthrin were chemically characterized. Using benchmark photosentizers and transient oxidants, the products resulting from indirect photolysis were also characterized. After chronological mapping of abiotic and microbiological degradative pathways over the course of a growing season, the timing of spray applications were modified in order to optimize NOW control. Research has contributed to delayed onset of resistance – a critical management tool, enhanced potential to mitigate maximum residue level (MRL) based export barriers, and improved environmental stewardship through reduced insecticide use.